JP6053935B2 - Mechanical fluid pump driven by a combustion engine - Google Patents

Description

  The present invention relates to a mechanical fluid pump that is driven by an internal combustion engine and supplies liquid, compressed gas or negative pressure to an automobile unit.

  The fluid pump may be a lubricant pump, a coolant pump, a negative pressure pump, a pump that supplies compressed liquid, or a pump that supplies compressed gas, eg, compressed air. The mechanical fluid pump is not driven by an electric motor but is directly connected to the combustion engine. As a result, the rotational speed of the fluid pump is proportional to the rotational speed of the combustion engine, so that even if there is no need for fluid supply or suction to create a negative pressure, The fluid pump is always rotating.

  U.S. Pat. No. 7,422,093 describes a fluid pump for supplying compressed liquid for hydraulic power steering. The fluid pump includes a magnetorheological clutch so that the pump capacity can be controlled based on the power and fluid demands of the power steering.

  For example, a critical fluid pump such as a lubricant pump, a coolant pump, or a negative pressure pump for a pneumatic brake assist unit cannot tolerate the risk of failure. A fluid pump with a clutch should be as compact as possible. In many applications, a relatively high torque needs to be transmitted by the clutch.

  It is an object of the present invention to provide a mechanical fluid pump driven by a combustion engine having a compact magnetorheological clutch.

  This object is solved by a mechanical fluid pump driven by a combustion engine having the features of claim 1.

  The fluid pump in the present invention includes an input shaft that is directly driven by a combustion engine, and a pumping unit having a pump rotor, and the pumping unit is for pumping a fluid that can be liquid or gas. The term “directly driven” is understood as the absence of a separable clutch between the rotating element of the engine and the input shaft of the pump. The input shaft of the pump can be driven by the engine via a belt, gears or by directly connecting to the engine camshaft or crankshaft.

  The clutch is realized as a magnetic viscous clutch in the form of a multi-plate clutch. The clutch comprises at least two radial input clutch disks and at least two radial output clutch disks, in which case a large number of radial clutch fluid gaps are formed between these clutch disks. Is done. The multi-plate configuration in the magnetorheological clutch allows for a compact diameter of the clutch and allows high torque to be transmitted from the clutch input side to the clutch output side.

  A radial clutch liquid gap disposed axially between the input clutch disk and the output clutch disk is filled with a magnetic viscous clutch liquid, which is relatively free when a magnetic field is present. It has a high viscosity and a relatively low viscosity when no magnetic field is present. The term liquid in this text, including magnetorheological liquids, should not be interpreted literally, but should be understood as a type of magnetorheological fluid that can cure in some way when activated by a magnetic field. The magnetic field for increasing the viscosity of the magnetic viscous clutch liquid is not generated by the electromagnetic means, but by a permanent magnet element that can move between the separation position and the engagement position. The magnetic flux of the permanent magnet element penetrating through the liquid gap is small, and the magnetic flux of the magnetic field penetrating through the clutch liquid gap is large at the engaged position. In the engaged position, the permanent magnet is disposed proximate to the clutch liquid gap, and in the separated position, the permanent magnet is located further away from the clutch liquid gap. The permanent magnet element is provided to rotate with the input clutch disk, so that the permanent magnet element always rotates at the rotational speed of the input shaft.

  The permanent magnet element is moved between a engaged position and a separated position by a separate magnet element actuator.

  Since the magnetic field penetrating the clutch liquid gap and the magnetorheological clutch liquid in the gap is not generated by the electromagnet, the magnetorheological clutch is engaged even when the pump control means and the control means for clutch operation fail. obtain.

  In general, the magnetorheological eddy current clutch may be combined with other automotive equipment near or not in the engine, or even for use outside the automobile.

  Preferably, the permanent magnet element is provided so as to be movable in the axial direction. Preferably, the permanent magnet is magnetized in the circumferential direction.

  The permanent magnet element is preferably pretensioned to its engaged position by a passive pretensioning element. If the actuator fails, the pretensioning element pushes the permanent magnet element into the engaged position. Such a configuration forms a clutch concept with a complete fail-safe function. The passive pretensioning element can be, for example, a spring or another permanent magnet. However, passive pretensioning elements do not require external energy to provide a pretensioning force.

  According to a preferred embodiment, the magnet chamber is provided radially inward of the clutch disk. The permanent magnet element is provided so as to be movable between the engagement position and the separation position in the magnet chamber. The clutch disk is disposed radially outside the magnet chamber and adjacent to the magnet chamber in the radial direction. Preferably, the radial plane of the clutch liquid gap intersects the permanent magnet element at the position of engagement of the permanent magnet element. In other words, the magnetic field of the engaged permanent magnet element typically penetrates the fluid liquid gap radially. Such a configuration allows for uniform penetration of the radial fluid liquid gap when the permanent magnet element is in its engaged position.

  The magnet chamber is a chamber in which the permanent magnet element is disposed so as to be movable between the engagement position and the separation position. Preferably, the longitudinal engagement section of the magnet chamber wall that intersects the plane of the clutch liquid gap is formed from a non-ferromagnetic material. As a result, the magnetic field of the permanent magnet element is not shielded radially in the engagement section of the magnet chamber wall, so that the magnetic field of the permanent magnet element penetrates the clutch liquid gap without any associated weakening. The radial thickness of the magnet chamber wall in the engagement section should be as small as possible, thereby minimizing the magnetic gap between the permanent magnet element and the clutch liquid gap.

  According to a preferred embodiment, the longitudinal separation section of the magnet chamber wall is formed from a ferromagnetic material, thereby shielding the magnetic field of the permanent magnet element against the clutch liquid gap at the separation position of the permanent magnet element. doing. The better the magnetic shielding of the permanent magnet at the permanent magnet separation position, the smaller the torque transmitted between the input clutch disk and the output clutch disk at the permanent magnet element separation position.

  Preferably, the actuator can be provided as a negative pressure actuator. The negative pressure actuator is not magnetized and does not generate an electromagnetic field through the clutch liquid gap filled with the magnetorheological clutch liquid.

  One embodiment of the invention will now be described with reference to the accompanying drawings.

1 shows a mechanical fluid pump driven by a combustion engine with a magnetorheological multi-plate clutch in longitudinal section in the engaged state. The fluid pump of FIG. 1 is shown in a separated state.

  1 and 2 show a typical motor vehicle configuration comprising an internal combustion engine 12 and a mechanical fluid pump 10 driven directly by the internal combustion engine 12. The fluid pump 10 may be designed as the negative pressure pump 10, but may be provided as a lubricating oil pump, a coolant pump, or the like. The internal combustion engine 12 is mechanically coupled directly to the input shaft 20 of the clutch 16 of the negative pressure pump 10, whereby the input shaft 20 always rotates together at a rotational speed that is directly proportional to the rotational speed of the internal combustion engine 12. .

  The clutch 16 is disposed between the input shaft 20 and the output shaft 21, and the clutch 16 is designed as a magnetic viscous multi-plate clutch 16. The clutch 16 connects the input shaft 20 to the output shaft 21 in the engaged clutch state as shown in FIG. 1, and connects the output shaft 21 to the input shaft 20 in the separated state as shown in FIG. Separate from. The output shaft 21 of the clutch 16 is directly connected to the negative pressure pumping unit 18 having the pump rotor 19. The clutch 16 includes four radial input clutch disks 62 and five radial output clutch disks 64. All the clutch disks 62, 64 are each located in one radial plane. Eight radial clutch liquid gaps 66 are formed between the clutch disks 62 and 64, and these gaps 66 are filled with the magnetorheological clutch liquid 28. Since the clutch liquid gap 66 is sealed and closed, the magnetic viscous clutch liquid 28 will not disappear.

  The permanent magnet element 32 is disposed radially inward and in the center of the clutch disks 62 and 64. The permanent magnet element 32 is provided as a cylindrical magnet body 30 that is provided so as to be movable in the axial direction within the cylindrical magnet chamber 22. The magnet chamber 22 is provided and formed by cylindrical chamber walls 25, 27, which chamber walls 25, 27 and engagement sections 24 intersecting the radial planes of the clutch disks 62, 64 and the clutch liquid gap 66. And the separation sections 26 that do not intersect the radial plane of the clutch disks 62, 64 and the clutch liquid gap 66. The magnet chamber wall 25 of the engagement section 24 is made of a non-ferromagnetic material such as aluminum or plastic. The magnet chamber wall 27 of the separation section 26 is formed of a ferromagnetic material, thereby shielding the magnetic field of the permanent magnet element 30 in the clutch liquid gap 66 at the separation position of the permanent magnet element 32 as shown in FIG. ing.

  In the engaged position, the permanent magnet element 32 is in close proximity to the radial clutch fluid gap that includes the magnetorheological clutch fluid 28 so that the magnetic field generated by the permanent magnet element 32 causes the magnetorheological viscosity in the clutch fluid gap 66 to be increased. The clutch liquid 28 is penetrated with the maximum magnetic flux.

  As shown in FIG. 1, the permanent magnet element 32 that is movable in the axial direction is pretensioned to the engagement position by the pretensioning element 44. This configuration forms a fail-safe function of the clutch 16 because the permanent magnet element 32 is always pushed into the engaged position even if the pneumatic actuator 42 fails.

  As long as the clutch 16 remains disengaged by driving the pneumatic actuator 42, the movable permanent magnet element 32 is retracted into and maintains that disengaged position, as shown in FIG. To do. In the separation position of the permanent magnet element 32, the magnetic field is shielded away from the clutch liquid gap 66, so that the magnetic flux in the clutch liquid gap 66 is relatively small, resulting in a magnetorheological clutch liquid. The viscosity of is relatively low. The clutch is disengaged.

  As soon as the clutch 16 is switched to the engaged state by deactivating the actuator 42, the movable magnet element 32 is pushed into the engaged position by the pretensioning element 44, as shown in FIG. In this state, the magnetic flux of the magnetic field penetrating the clutch liquid gap 66 is relatively large, thereby making the viscosity of the magnetorheological clutch liquid relatively high. In this engaged state, the output shaft 21 rotates at the same rotational speed as the input shaft 20. The output shaft 21 drives the pump rotor 19 of the pressure feeding unit 18, whereby the pressure feeding unit 18 pumps the fluid.

Claims (7)

An input shaft (20) directly driven by the combustion engine (12);
A pumping unit (18) having a pump rotor (19);
A magnetorheological multi-plate clutch (16) between the input shaft (20) and the pump rotor (19), the clutch (16) comprising at least two radial input clutch disks (62) and At least two radial output clutch disks (64) with at least two radial clutch liquid gaps (filled by magnetorheological clutch liquid (28)) between the clutch disks (62, 64). 66), a magnetic viscous multi-plate clutch (16),
A permanent magnet element (32) movable between an engagement position and a separation position, wherein in the engagement position, the magnetic field of the permanent magnet element is a relatively large magnetic flux and the clutch liquid gap (66). ) And in the separated position, the magnetic flux of the permanent magnet element passing through the clutch liquid gap (66) is smaller than the magnetic flux in the engaged position, and the movable permanent magnet element (32) ,
An actuator (42) for moving the permanent magnet element (32) between the engagement position and the separation position;
Equipped with a,
A magnet chamber (22) is provided radially inward of the clutch disk (62, 64),
A machine driven by a combustion engine, wherein the permanent magnet element (32) is provided in the magnet chamber (22) so as to be movable between the engagement position and the separation position. Type fluid pump (10).   The mechanical fluid pump (10) driven by a combustion engine according to claim 1, wherein the permanent magnet element (32) is movably provided in an axial direction.   A mechanical fluid driven by a combustion engine according to claim 1 or 2, wherein the permanent magnet element (32) is pretensioned to the engagement position by a passive pretensioning element (44). Pump (10). Radial planes of the clutch liquid gap (66) is in said engaged position, said intersecting the permanent magnet element (32) is driven by the combustion engine of any one of claims 1 to 3 Mechanical fluid pump (10). Wherein it intersects the plane of the clutch liquid gap (66), longitudinally engaging segment of the wall (25) of the chamber for the magnet (24) is formed from a non-ferromagnetic material, of claims 1-4 A mechanical fluid pump (10) driven by a combustion engine according to any one of the preceding claims. The longitudinal separation section (26) of the magnet chamber wall (27) is formed of a ferromagnetic material, so that in the separation position of the permanent magnet element (32) in the clutch liquid gap (66). the shields the magnetic field of the permanent magnet elements (32), a mechanical fluid pump driven by the combustion engine of any one of claims 1 to 5 (10). Wherein the actuator is a negative pressure actuator (42), a mechanical fluid pump driven by the combustion engine of any one of claims 1 to 6 (10).

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